1. Field of the Disclosure
The present disclosure relates generally to imaging systems, such as scanners, copiers, and multi-function imaging systems, and more particularly, to a system for previewing and imaging a document.
2. Description of the Related Art
In various imaging systems, such as a scanner, a copier, and a multi-function imaging system (like an All-in One (AIO) printer), an original document is placed upon an imaging surface/platen made of a material, such as glass, for scanning, copying, printing and other such purposes.
A user of an imaging system may encounter difficulties in appropriately aligning an original document on the scanner's platen in order to obtain an optimally scanned image, such as an image with maximum scan quality and an image scanned in a shortest possible time. For example, in a typical flatbed scanner, a scan bar of the scanner moves under a platen in order to scan the entire length of an original document, starting at a calibration, home position, or edge on one end portion of the platen. Scans are made most optimally when the original document is abutted against the calibration edge and not against the other end portion. In another instance, some flatbed scanners provide a “smart scanning” mode where a user may place a document, such as a 4 inch×6 inch photo, anywhere on a platen. The scan bar may then scan the entire area of the platen. Subsequently, the scanner software discerns the photo apart from the scan background (i.e., extra area of the platen) and outputs an image file with the photo scan data. However, the aforementioned operation is complex and may take more time than a case where the photo may be placed at a preferred, known position on the platen. Accordingly, guiding a user about positioning an original document on a platen of different types of imaging systems may be advantageous. However, guiding, instructing or communicating to a user about aligning an original document along a home position (i.e., reference point) of an imaging system has remained a problem for various manufacturers of scanners, copiers, AIO printers and the like.
Typically, a manufacturer of an imaging system may provide indications, such as moldings, painted arrows and markings, adjacent to a home position on a housing of the imaging system. However, such indications may be overlooked or missed by the user. For example, a user may be unable to perceive marks provided along an edge of a scanner's housing. More specifically, in an AIO printer that includes an auto document feeder, the flatbed scan home position is typically located at a rear corner portion of the printer near a calibration strip for optimum scan response time. Unfortunately, such indicators may only be visible when a scanner lid or cover is opened to a substantial angle. Accordingly, the user may fail to align an original document along the home position as intended, thereby leading to unacceptable results and resulting in the user needing to reproduce copies, scans, prints, etc. again. Furthermore, providing indication about orientation of the original document and reminding the user to align the original document in a correct position or location (e.g., abutted to the home position or centered along an edge of the imaging system) and in a correct orientation (e.g., either portrait or landscape) may be challenging. Additionally, the indications may wear off over a period of time, and the provision of any such indication, particularly painted arrows, may add to costs associated with the imaging system.
In addition, various imaging systems, such as a camera scan system, include a lens that has a spherical surface. Accordingly, the image quality of the area of an original document near the center portion of the platen may be better than the areas of the original document that are positioned nearer to the edges of the platen. FIG. 1 depicts such an image quality drop-off map 10 for a camera scan system prevalent in the prior art. The camera scan system may be employed in a scanner, copier, facsimile machine or other imaging system for performing a scanning, copying or faxing operation and may include a platen or scan glass 100. The scan glass 100 may be utilized to carry a document (not shown) thereon for scanning, copying or faxing purposes.
The camera scan system of FIG. 1 further includes a spherical lens 200, which is used to take an image of the document placed over the scan glass 100. The spherical lens 200 is an optical imaging lens available in the market. Further, the spherical lens 200 has better imaging capability near a center portion (not numbered) of the spherical lens 200 rather than towards edges (not numbered) of the spherical lens 200. As shown in FIG. 1, the image quality drop-off map 10 depicts a decrease in image quality of the document placed over the scan glass 100. More specifically, the quality of the image decreases near edges (not numbered) of the scan glass 100 as compared to the quality of the image near a center portion (not numbered) of the scan glass 100, as shown by a straight arrow 300 pointing from the center portion of the scan glass 100 towards an edge (not numbered) of the scan glass 100. Accordingly, the image of the document near respective edges of the document may not be clearly visible, thereby leading to unacceptable quality and or unwanted repetition of the scanning, copying or faxing operation.
The image quality drop-off map 10 has been shown to be topographically circular for the ease of depiction only. It may be evident that the image quality drop-off map 10 may be of any other topographic shape.
Various approaches for correcting distortion of images obtained through the imaging systems that use a camera lens, have been devised. However, imaging systems employing such approaches to correct the distortion of images are typically processor intensive, impacting electronic architecture and overall cost. Further, various approaches for obtaining a preview of original documents prior to imaging operations have been devised for minimizing the problems associated with alignment of the original documents over respective platens of the imaging systems. Thus, such approaches have been unable to facilitate an appropriate alignment of the original documents over the platens of the imaging systems to obtain optimally scanned images using less financial and/or labor resources.
Accordingly, there persists a need for an efficient and cost-effective system for previewing and imaging a document that facilitates an appropriate alignment of the document over a platen of the system, at a correct location and in a correct orientation for an imaging operation.